The effect of interface topography for Ultrasonic Consolidation of aluminium

Abstract

Ultrasonic Consolidation (UC) is an additive manufacturing technology which is based on the sequential solid-state ultrasonic welding of metal foils. UC presents a rapid and adaptive alternative process, to other metal-matrix embedding technologies, for 'smart' metal composite material production. A challenge that exists however relates to optimising, for bond density and plastic flow, the interlaminar textures themselves that serve as the contact surfaces between the foils. UC employs a sonotrode connected to a transducer to exude ultrasonic energy into the metal foil being sequentially deposited. This sonotrode to metal contact imparts a noteworthy topology to the processed metals surface that in turn becomes the crucial substrate topology of the subsequent layers deposition. This work investigated UC processed Al 3003 samples to ascertain the effect of this imparted topology on subsequent layer deposition. Surface and interlaminar topology profiles were characterised using interferometry, electron and light microscopy. The physical effect of the topology profiles were quantified via the use of peel testing.The imparted topology profile was found to be of fundamental significance to the mechanical performance and bond density achieved within the bulk laminate during UC. The UC process parameters and sonotrode topology performed a key role in modifying this topology profile. The concept of using a specifically textured sonotrode to attain desired future smart material performance via UC is proposed by the authors. ABSTRACTUltrasonic Consolidation (UC) is an additive manufacturing technology which is based on the sequential solid-state ultrasonic welding of metal foils. UC presents a rapid and adaptive alternative process, to other metal-matrix embedding technologies, for "smart" metal composite material production. A challenge that exists however relates to optimising, for bond density and plastic flow, the interlaminar textures themselves that serve as the contact surfaces between the foils.UC employs a sonotrode connected to a transducer to exude ultrasonic energy into the metal foil being sequentially deposited. This sonotrode to metal contact imparts a noteworthy topology to the processed metals surface that in turn becomes the crucial substrate topology of the subsequent layers deposition. This work investigated UC processed Al 3003 samples to ascertain the effect of this imparted topology on subsequent layer deposition. Surface and interlaminar topology profiles were characterised using interferometry, electron and light microscopy. The physical effect of the topology profiles were quantified via the use of peel testing.The imparted topology profile was found to be of fundamental significance to the mechanical performance and bond density achieved within the bulk laminate during UC. The UC process parameters and sonotrode topology performed a key role in modifying this topology profile. The concept of using a specifically textured sonotrode to attain desired future smart material performance vi...

Solid-state additive manufacturing for metallized optical fiber integration

“…The topography that results from direct sonotrode-foil contact has been shown to have a marked effect on the interlaminar bonding dynamics of a UAM structure [28]. By measuring the change in surface roughness as a result of embedding both coated and uncoated fibers, it is possible to predict the bonding characteristics likely to result from depositing a fourth layer on top of the covering layer (see Section 3.4).…”

“…Direct imprint of the sonotrode topography onto the UAM substrate can lead to regions of intimate contact between upper and lower foils, which are indistinguishable from each other, but are not metallurgically bonded [28]. This can cause discrepancies in LWD analysis due to difficulties in differentiating these areas from genuinely bonded regions.…”

Power ultrasonics for additive manufacturing and consolidating of materials

“…In addition to these bond Figure 13.7 Schematic of the formation machines integrated machining centre. Typically, the greater the amplitude the higher the energy input into the foil-to-part interface during UAM; higher energy input has been shown to result in superior bond strength and greater plastic flow during USW (Friel et al, 2010a;Hopkins et al, 2011;Kong et al, 2004b;Li and Soar, 2009;Tuttle, 2007;Yang et al, 2009;Weare et al, 1960). Typically, the greater the amplitude the higher the energy input into the foil-to-part interface during UAM; higher energy input has been shown to result in superior bond strength and greater plastic flow during USW (Friel et al, 2010a;Hopkins et al, 2011;Kong et al, 2004b;Li and Soar, 2009;Tuttle, 2007;Yang et al, 2009;Weare et al, 1960).…”

“…The modified topology of the sonotrode is necessary to efficiently transfer kinetic energy to the bond interface during the oscillations and weld pressure and to induce sufficient plastic flow for bonding (Friel et al, 2010a;Johnson, 2008;Johnson et al, 2011;Li and Soar, 2009). The roughened surface creates a mechanical coupling and prevents energy loss through slippage (Weare et al, 1960).…”

New concept to aid efficient fibre integration into metal matrices during ultrasonic consolidation

“…Until now, research on high fibre volume integration has shown that the delivery of sufficient energy to the interfaces was insufficient and led to poor bonding quality. 7,12,13 To approach high volume fibre integration without high amplitudes yet reducing the required amount of plastic flow and secure and accurate placement of the fibres, a method based on creating trenches in post-UC samples via a laser was pursued. Figure 2 displays the schematic representation of the proposed method.…”